|Publication number||US6981768 B2|
|Application number||US 10/283,949|
|Publication date||Jan 3, 2006|
|Filing date||Oct 30, 2002|
|Priority date||Oct 30, 2002|
|Also published as||US20040085430|
|Publication number||10283949, 283949, US 6981768 B2, US 6981768B2, US-B2-6981768, US6981768 B2, US6981768B2|
|Inventors||Thomas A. Saksa, Grant K. Garner|
|Original Assignee||Hewlett-Packard Development Company, Lp.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (4), Classifications (10), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
An inkjet print recording system is a type of non-impact printing device which forms characters, symbols, graphics or other images by controllably spraying drops of ink. The inkjet system typically includes a cartridge which houses a printhead. The printhead has very small nozzles through which ink drops are ejected. To print an image the pen typically is propelled back and forth across a media sheet, while the ink drops are ejected from the printhead in a controlled pattern.
Inkjet print recording systems can be used in a variety of devices, such as printers, plotters, scanners, facsimile machines, copiers, and the like. There are various forms of inkjet printheads, including, for example, thermal inkjet printheads and piezoelectric printheads. In a thermal inkjet printing system, ink flows along ink channels from a reservoir into an array of vaporization chambers. Associated with each chamber is a heating element and a nozzle. A respective heating element is energized to heat ink contained within the corresponding chamber. The corresponding nozzle forms an ejection outlet for the heated ink. As the pen moves across the media sheet, the heating elements are selectively energized by a controller, which causes ink drops to be expelled in a controlled pattern. The ink drops dry on the media sheet shortly after deposition to form a desired image (e.g., text, chart, graphic or other image).
Some of the technologies for delivering ink to paper with a hand held pen, include ball point pen technology, felt tip pen technology, fountain pen technology, and quill pen technology. Each of these pen types are different with regard to ease of use, cost, print quality, and impacts on the writer. Different visual effects are sometimes observed for the different pen types. Also, different pressing forces are required of the pen holder when applying ink to the paper.
A hand held inkjet pen includes a housing, an ink reservoir, an inkjet printhead and a spacer. The ink reservoir is located within the housing. The inkjet printhead is located toward a distal end of the housing, and includes a plurality of nozzles for ejecting ink received from the reservoir. The spacer is located at the distal end of the housing for contacting a media sheet. Force applied to the spacer selects an on state for controlling ejection of ink from the plurality of nozzles.
The printhead 14 includes a plurality of inkjet nozzles. Each nozzle includes an inkjet chamber with a firing resistor and an outlet orifice. Ink is received into each chamber from the reservoir 12. The firing resistor is activated to eject a droplet of ink through the outlet orifice.
In addition, the spacer is coupled to the on-off control 18. In one embodiment the on-off control 18 is formed by a strain gauge 26. The strain gauge 26 defines an on state when a prescribed amount of pressure is applied at the spacer 24. Such pressure is applied as the operator holding the pen presses the spacer to the media 20. When the prescribed pressure is applied, the pen 22 ejects ink onto the media 20. When the pressure is removed or becomes less than the prescribed pressure, the strain gauge 26 returns to the off state causing ink output to cease.
The pen 22 also includes a controller 28 and a power source 30. The power source may, for example, be a battery packaged in the housing 16 and accessible for replacement as the battery life diminishes. The controller 28 is coupled to the on-off control 18/strain gauge 26 and the inkjet printhead 14. While the on-off control 18 defines the on state the controller 28 keeps the printhead 14 active so as to eject ink. While the on-off control 18 defines the off state, controller keeps the printhead inactive so as not to eject ink.
In some embodiments the pen also includes an optical sensor 32. The sensor 32 is positioned to sense in the vicinity of the pen's output field (e.g., in the vicinity of the pen tip, the pen spacer and the pen printhead. In one embodiment the sensor 32 serves as an input device for allowing an operator to select specific functional features of the pen. For example, in a pen having the capability to print varying colors, the sensor 22 scans a colored surface and sets the pen color to such surface's color. The colored surface can be scanned from a palette accompanying the pen or can be scanned from a random surface selected by the operator. In this manner, the sensor provides the pen with a learning capability.
The random surface can be sampled from any object in the user environment. In one application, the pen is used as a touch-up device. The pen senses the desired surface to be programmed to the surface's color. The pen then is used to apply ink at blemishes elsewhere on the surface to touch-up the surface with matching color. Alternatively, the sampled color is saved and later output for color sampling or reproduction by another device. For example, the pen can reproduce the color by outputting ink or can link to another device to output a signal which specifies or otherwise identifies the previously sensed color. In one embodiment, the sampled color is downloaded in a digital or analog encoded signal through an interface 33 to a device which produces color-matched paint, cloth, or other color media. The interface 33 in various embodiments is an electrical interface, an infrared interface, or an optical interface. In other embodiments the interface 33 is omitted, and the color is reproduced in ink output from the printhead 14.
In an alternative embodiment the output sensor 32 is implemented with the controller 28 to detect pen 22 angle 50 relative to the writing surface 52, as shown in
In another embodiment pen 22′ further includes a compensation adjustment input 58. In such embodiment the sensor 32 is used for tracking the pen 22 relative to the writing surface 52. Motion is tracked along various axes 54, 56. The compensation adjustment input allows the operator to adjust pen output to compensate for a trembling hand (e.g., pen shaking). For example, an operator with a trembling hand will direct a conventional pen to produce jagged lines. Referring to
As the pen motion is tracked by the sensor 32, the selected sensitivity is used by control processing to determine what motion variation is considered to be undesired pen shaking as opposed to desired pen direction change. In some embodiments, the sensor 32 may be an accelerometer which measures the instantaneous acceleration of the pen. This signal is processed to track pen displacement of the pen spacer 24 over time. The displacement information is filtered to distinguish between low frequency changes in displacement (e.g., taken to be the intended motion of the pen) and the higher frequency changes in displacement occurring within the slower frequency changes (e.g., the shaking occurring while moving the pen). The threshold for distinguishing between low frequency displacements and high frequency displacements may be varied using the sensitivity adjustment device. The sensitivity control device selects or adjusts one or more compensation control filters (not shown). In some embodiments changes in pen acceleration are detected. Acceleration changes exceeding a threshold change correspond to shaking. High frequency shaking is filtered out contributing to a natural writing experience. The inkjet printhead nozzle firing pattern is adjusted by the control processing based on the filter output and the sensitivity adjustment so that, in effect, all or a portion of the shaking motion is filtered out. The result is an improvement in the writing quality, specifically an improved smoothness to the lines and lettering 62.
The user interface 68 may vary according to the embodiment. In an exemplary embodiment the user interface includes a one-line LCD 70 and one or more buttons 72 a, 72 b. In some embodiments the input buttons may be integral to the LCD, as in a touch-sensitive LCD. The operator uses the buttons to display and select pen functional options. Such options include those described above. By way of example, various ink output styles may be selected, such as: ink color, line thickness, ink boldness, ink texture. In some embodiments, a superimposed output pattern may be selected. Examples were previously described with regard to
In various embodiments the controller 28 may be formed using an integrated circuit microcontroller. Alternatively, a controller embodiment may be formed using an electrical circuit 90, including an oscillator 92, a sequencer 94 and a plurality of firing transistors 96. Referring to
To improve consistency among ink drops output from each nozzle, it is desirable that the drive signal triggering a nozzle have substantially the same amount of energy as the drive signal for the other nozzles. More specifically, it is desirable that the active pulse of a given firing signal 100 a–n delivers substantially the same amount of energy to its corresponding nozzle firing resistor as the active pulse of any other firing signal 100 a–n. Further, an active pulse of a given firing signal 100 a–n delivers substantially the same amount of energy to its corresponding nozzle firing resistor as any prior or later active pulse of the same firing signal 100. The amount of energy may be set for a given pen architecture.
One manner of improving consistency among each active pulse of each firing signal 100 is to generate a substantially constant pulse width and a substantially constant pulse voltage level for each such active pulse. When implementing a battery-powered pen, there is a challenge in achieving such goal because the battery's output voltage typically drops as the battery life progresses. In one embodiment a voltage regulator is used to maintain the uniformity among active pulses of each firing signal over the life of the battery. To avoid the added cost and complexity of including a voltage regulator, a non-linear device may be implemented in an alternative embodiment.
Referring again to
While the above is discussed in terms of preferred and alternative embodiments, the invention is not intended to be so limited.
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|US4412232 *||Apr 15, 1982||Oct 25, 1983||Ncr Corporation||Ink jet printer|
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|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7393098 *||Dec 16, 2004||Jul 1, 2008||SOCIéTé BIC||Liquid jet writing instrument|
|US20050106547 *||Oct 5, 2004||May 19, 2005||Ngai Keung Metal & Plastic Mfy. Ltd.||Device for use as learning aid or educational toy|
|US20050206690 *||Dec 16, 2004||Sep 22, 2005||Xavier Bich||Liquid jet writing instrument|
|US20100245419 *||Mar 25, 2010||Sep 30, 2010||G2 Inventions, Llc||Inkjet cartridge pen|
|International Classification||B41J29/393, B41J2/175, B41J3/36|
|Cooperative Classification||B41J3/36, B41J29/393, B41J2/1752|
|European Classification||B41J2/175C3, B41J29/393, B41J3/36|
|May 13, 2003||AS||Assignment|
Owner name: HEWLETT-PACKARD DEVELOPMENT COMPANY, LP., TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAKSA, THOMAS A.;GARNER, GRANT K.;KOLL, ANDREW;AND OTHERS;REEL/FRAME:014057/0236;SIGNING DATES FROM 20030428 TO 20030507
|Jul 6, 2009||FPAY||Fee payment|
Year of fee payment: 4
|Aug 16, 2013||REMI||Maintenance fee reminder mailed|
|Jan 3, 2014||LAPS||Lapse for failure to pay maintenance fees|
|Feb 25, 2014||FP||Expired due to failure to pay maintenance fee|
Effective date: 20140103